光敏推进剂激光烧蚀过程建模与仿真

相较于传统大卫星,微小卫星具有结构紧凑、质量轻便和成本低廉的特点。然而,受功率和质量负载的限制,微小卫星一般不装备推进系统,其航线也局限于近地轨道。为扩展微小卫星的功能,满足日益复杂的任务需求,需给其配备合适的微推进系统。固体推进系统具有结构简单、寿命长、可靠性高的优点,但无法重复启动。为得到可重复启动的固体微推进系统,设计了一种非自持燃烧的光敏推进剂,采用激光控制其燃烧。在背压为大气压的环境下,利用高速摄像机拍摄燃烧过程并记录燃速。之后,对光敏推进剂的激光烧蚀过程进行建模。分析结果表明:激光可控制光敏推进剂的燃烧,燃速与激光强度成线性关系;该光敏推进剂的最小激光点火强度为0.28 W/mm~2;燃速计算值与实测值的误差在10%以内,证明该数学模型具备工程应用价值。

Modeling and Numerical Simulation of Laser Ablation of Laser Sensitive Propellant

Compared with the conventional satellite,the microsatellite is characterized by compact structure, light mass and low cost. However, due to the limitation of load mass and power, the microsatellite is not equipped with propulsion system in normal case, and the flight course is limited to the low-earth orbit. In order to expand the application of microsatellite, it needs a suitable propulsion system for complex missions. The solid propulsion system has the advantages of simple structure, long lifetime and high reliability, but it cannot conduct stop-and-restart combustion. In this paper, a laser-sensitive propellant whose combustion can be controlled by infrared laser is designed. The burning rates of laser-sensitive propellant are measured by digital high-speed camera. The model of laser ablation process for laser-sensitive propellant is established. The results show that the laser can control the combustion of laser-sensitive propellant, and the burning rates are proportional to the laser power.The propellant can be ignited at laser power density as low as 0.28 W/mm². The calculation error of burning rates is less than 10%, proving that the mathematical model has practical engineering application value.